For Marketing we're using HubSpot which can be pretty costly but it's good.

The purchase price, loan amount, your interest rate, whether you need mortgage insurance, your homeowner's insurance cost, property taxes, and your current monthly debt obligations all factor into your DTI.  

Buyer pays closing costs & loan doc fees: $3,800 approx.Total Entry Fee: $23,800 to close -- or 9% of the purchase price!

whats the cost?

I have the pro yearly plan but if you have one property it may be best to opt for the starter plan and use a less costly lease builder like EZ Landlord.

If Tenant Defaults under this Lease, Landlord may exercise all rights and remedies available under applicable law, including the right to: (i) terminate this Lease; (ii) regain possession of the Property through an eviction or similar process; (iii) recover from Tenant all unpaid Rent, including unpaid Monthly Rent, Additional Rent, Late Fees and, if applicable, holdover Rent for the period prior to Tenant’s delivery of possession of the Property to Landlord; (iv) recover all Rent payable under this Lease for the period from the date of termination for Tenant Default through the stated Expiration Date, less the amount Landlord is able to collect from any replacement tenants for that period; and (v) recover allreasonable costs and expenses incurred by Landlord in repairing any damage to the Property, caused by the improper useby any Occupant or any guests of an Occupant, less any amounts obtained from the Security Deposit.

So, we incur little if any cost on prelims.

Your only issue is that STR management is costly in Austin, up to 25 percent.

There are other services, and they will simply put out a higher volume of calls vs some of these VAs Any idea how much Lamassu leads cost?

You should look to conduct a cost segregation study so that you can accelerate more of your depreciation against your income.